Gum Drops

I have been gaming since the early 80s, and one thing that hasn't changed in all those years is the impact music has on a game. I couldn't begin to tell you the high score I got on Tetris for the Gameboy, but I'm certain I could hum a few bars of the music. And who could froget the instrumentals that played in the background of Super Mario Brothers? I've played some games that have been less than stellar, but I still remember the experience because of the music. So why would a developer NOT want to have music in their game?